The present invention relates to a novel method for making shaped flexible tubes or hoses, in particular curved flexible tubes.
The invention also relates to the shaped flexible tube made by the inventive method.
The field of the invention is that of the methods used for making shaped flexible tubes in general, in particular tubes including either one or more bent portions, and which are made of a curable material.
At present, the flexible tubes of the above mentioned type, made of a flexible elastomeric curable material, such as rubber and the like, as they are industrially made by a method different from a straight mandrel method, have free end portions thereof, that is end portions which are lacking of possible fittings or “rubber heel members”, made as a single piece, and which are usually necessary for coupling the tube to target utilizer devices.
Thus, conventional curved tubes having the above disclosed construction require auxiliary clamping operations, for clamping the desired fittings which, accordingly, are not structurally joined or integral with the body of the tube.
Thus, prior tubes of the above disclosed pipes are affected by drawbacks, related to the mentioned requirements of performing auxiliary processing operations on said tubes, and due to the further requirement of using auxiliary elements such as clamping bands, ring-nuts and the like.
To overcome the above mentioned drawbacks, it is known in the art to make flexible pipes or hoses on a straight mandrel, the pipes being held in a desired curved or bent position by a metal coil insert, operating to receive and hold the desired shape of the tube.
Such an approach, however, has the drawback of requiring an additional provision of a metal coil or spiral element to be built-in or embedded in the pipe construction; such a coil element, actually, is sometimes undesirable, since such a coil or spiral element would negatively affect the end weight of the tube and its making costs.